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Drop select frame variables from the KinematicsSolver object


removeFrameVariables(ks,ids) drops from the KinematicsSolver object ks the frame variables named in ids. Frame variables capture the transforms between any two given frames. Use this function to remove just a subset of frame variables if they become obsolete. Variables of the same type and in the same group must be removed together.

The output is an updated table with the frame variables—those that remain—in rows. Each row gives the ID of a variable, the base frame against which its transform is defined, the follower frame which the transform describes, and the unit for its numerical value.

Frame and joint variables comprise the whole of kinematic variables in a KinematicsSolver object. They can function as targets to constrain the multibody configuration for which to solve the unknowns, as guesses to bias the solution toward one of equally plausible alternatives when several exist, and as outputs—the unknowns in the analysis.

The figure shows the variables of a general KinematicsSolver object. Target (T), guess (G), and output (O) variables can be joint variables (J) or frame variables (F). Joint variables are native to the object and can be assigned from its start as targets, guesses, and outputs. Frame variables must first be created with addFrameVariables.

Input Arguments

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A KinematicsSolver object is the representation of a Simscape Multibody model used for kinematic analysis.

Example: ks = simscape.multibody.KinematicsSolver('sm_double_pendulum')

Data Types: KinematicsSolver object

Identifiers of the kinematic variables to use. Enter the identifiers as shown in the ID column of the jointPositionVariables or jointVelocityVariables, for joint variables, or frameVariables, for frame variables.

Example: 'j1.Rz.q'

Data Types: char | string

Introduced in R2019a